1. Week #27 Bell ringers and quiz 8 th grade math

2. Bell Ringer Monday Four figures have the following dimensions: Rectangular prism: l=2 in; w=4 in; h=7 in Cylinder: r=4 in; h=6 in Cone: r=4 in; h=6 in Rectangular pyramid: l=2 in; w=4 in; h=7 in 1. What is the probability that a figure chosen at random will have a volume greater than 150 cubic inches? 2. Two figures are pulled one at a time. After you pull the first time, you do not replace. What is the probability both figures will have a volume less than 125 cubic inches? 3. Calculate the mean.

3. Rectangular prism: l=2 in; w=4 in; h=7 in Cylinder: r=4 in; h=6 in Cone: r=4 in; h=6 in Rectangular pyramid: l=2 in; w=4 in; h=7 in

4. Rectangular prism: l=2 in; w=4 in; h=7 in V=56in 3 Cylinder: r=4 in; h=6 in V=301.44in 3 Cone: r=4 in; h=6 in V=18.67in 3 Rectangular pyramid: l=2 in; w=4 in; h=7 in V=100.48in 3 1.What is the probability that a figure chosen at random will have a volume greater than 150 cubic inches? 2. Two figures are pulled one at a time. After you pull the first time, you do not replace. What is the probability both figures will have a volume less than 125 cubic inches?

5. Rectangular prism: l=2 in; w=4 in; h=7 in V=56in 3 Cylinder: r=4 in; h=6 in V=301.64in 3 Cone: r=4 in; h=6 in V=18.67in 3 Rectangular pyramid: l=2 in; w=4 in; h=7 in V=100.48in 3 3. Calculate the mean.

6. Quiz Monday Roderick is building a model of an actual airplane with a length of 20 feet. What other information is necessary in order to find x, the length of the model airplane? F The ratio of the length of the model airplane’s tail to the length of its wing G The speed of the model airplane H The scale factor used J The model airplane’s wingspan

7. What information is needed to find x? Anything involving dilations must have a scale factor. If one dimension is known, the dimension of the similar figure can be found by multiplying by the scale factor. Roderick is building a model of an actual airplane with a length of 20 feet. What other information is necessary in order to find x, the length of the model airplane? The scale factor is needed to find x. Actual length = 20 feet x = model length Dilation

8. 1.Calculate the area of each triangle. 2.Calculate the perimeter of each triangle. 3.Are the figures similar? 4.Calculate the probability of randomly picking a triangle and it is a right triangle. 3 4 5 8 6 11 A B Bell Ringer Tuesday

9. 1.Calculate the area of each triangle. 2.Calculate the perimeter of each triangle. 3 4 5 8 6 11 A B

10. 3.Are the figures similar? 3 4 5 8 6 11 A B

11. 3 4 5 A 3 2 +4 2 =5 2 9+16=25 25=25 Right Triangle 8 6 11 B Not Right Triangle 6 2 +8 2 =11 2 36+64=121 100 ≠ 121 4. Calculate the probability of randomly picking a triangle and it is a right triangle.

12. Quiz Tuesday A pattern of equations is shown below. 1% of 800 = 8 2% of 400 = 8 4% of 200 = 8 8% of 100 = 8 16% of 50 = 8 Which statement best describes this pattern of equations? F. When the percent is doubled and the other number is halved, the answer is 8. G. When the percent is doubled and the other number is doubled, the answer is 8. H. When the percent is increased by 2 and the other number remains the same, the answer is 8. J. When the percent remains the same and the other number is increased by 2, the answer is 8.

13. Which statement is the best description of the pattern? I found the pattern involving the percents. All the percents were doubled. I found the patter involving the whole numbers. All whole numbers were cut in half. They all were equivalent to 8. A pattern of equations is shown below. 1% of 800 = 8; 2% of 400 = 8; 4% of 200 = 8; 8% of 100 = 8; 16% of 50 = 8. Which statement best describes this pattern of equations? Statement F is the best description of the pattern. 1% of 800 = 8 2% of 400 = 8 4% of 200 = 8 8% of 100 = 8 16% of 50 = 8

14. Bell Ringer Wednesday There are 10 marbles in a bag. 4 are red, 2 blue, 1 yellow, and 3 green. You are going to pick two marbles one at a time. After you pick a marble, you do not replace it. (Treat each question independent of the other ones). 1. P(red and green) 2. P(yellow and blue) 3. P(2 blues) 4. P(2 yellows) 5. Calculate the mode 6. What percent are green?

15. There are 10 marbles in a bag. 4 are red, 2 blue, 1 yellow, and 3 green. You are going to pick two marbles one at a time. After you pick a marble, you do not replace it. 1. P(red and green) 2. P(yellow and blue) 3. P(2 blues)

16. There are 10 marbles in a bag. 4 are red, 2 blue, 1 yellow, and 3 green. You are going to pick two marbles one at a time. After you pick a marble, you do not replace it. 4. P(2 yellows) 5. Calculate the mode 6. What percent are green?

17. Quiz Wednesday Trace paid Dalton $15.50 for a combination of 15 baseball and football cards. The baseball cards were $1.50 each, and the football cards were $0.50 each. How much did Trace spend on the football cards?

18. How much was spent on football cards? I guessed and checked to find the right combination. I started with 10 baseball cards. When I multiplied that by $1.50, I got $15. I would still need 5 football cards, so 10 baseball cards is too much. I multiplied the number of cards by the price per card. The right combination is 8 baseball and 7 football. Trace paid Dalton $15.50 for a combination of 15 baseball and football cards. The baseball cards were $1.50 each, and the football cards were $0.50 each. How much did Trace spend on the football cards? $3.50 is spent on football cards. Spent $15.50 15 total cards Baseball $1.50 Football $0.50

19. Bell Ringer Thursday Sheila made a scale drawing of a room. The actual room has a width of 16 feet and a length of 24 feet. Her drawing has a length of 3 feet. 1. What type of dilation occurred? 2. Calculate the scale factor. 3. What is the width, in inches, of the scale drawing of the room? 4. Calculate the area of the scale drawing of the room. 5. Based on the dilation, how is the perimeter affected?

20. Sheila made a scale drawing of a room. The actual room has a width of 16 feet and a length of 24 feet. Her drawing has a length of 3 feet. 1. What type of dilation occurred? 2. Calculate the scale factor.

21. Sheila made a scale drawing of a room. The actual room has a width of 16 feet and a length of 24 feet. Her drawing has a length of 3 feet. 3. What is the width, in inches, of the scale drawing of the room? 4. Calculate the area of the scale drawing of the room.

22. Sheila made a scale drawing of a room. The actual room has a width of 16 feet and a length of 24 feet. Her drawing has a length of 3 ft. 5. Based on the dilation, how is the perimeter affected?

23. Quiz Thursday A water tank contains 2,500 gallons. A faucet attached to the tank releases water at a constant rate of 5 gallons per minute. If the faucet is left open for 1 hour and no other water is released, which equation can be used to find r, the number of gallons of water remaining in the tank? A. r = 2,500 ÷ 5 B. r = 2,500 – 60 C. r = 2,500 – 60(5) D. r = 2,500 ÷ 60(5)

24. Which equation can be used? Since 5 gallons of water is released per minute, I multiplied 5 by the number of minutes the water was released. It was released for one hour, so that is 60 minutes. To find the number of gallons left, I subtracted the water loss from the volume of the tank. A water tank contains 2,500 gallons. A faucet attached to the tank releases water at a constant rate of 5 gallons per minute. If the faucet is left open for 1 hour and no other water is released, which equation can be used to find r, the number of gallons of water remaining in the tank? Equation C can be used to find the number of gallons left. Holds 2500 gallons Releases 5 gallons per minute Open for 1 hour r = number of gallons in tank